ato ‘syā na meyaḥ kaścid api dharmo ‘sti. ato nirdhūtanikhilabhedavikalpanirdharmaprakāśamātraikarasā kūṭasthanityā saṃvid evātmā paramātmā ca. yathāha yānubhūtir ajāmeyānantātmā iti. saiva ca vedāntavākyatātparyabhūmir iti (ĀS, pp. 29–30 of the 1942 edition)

Therefore this (consciousness) has no characteristic as its knowable content. Therefore, this very consciousness is eternal, uniform and it consists of light-only, without characteristics, in which all conceptualisations of difference have been dissolved. This consciousness alone is the self (ultimately identical with the single brahman, but illusory identified as one’s own self) and the supreme self (i.e., the brahman). As it has been said: ”That experience (i.e., consciousness) is unborn, cannot become a knowledge content, it is endless, it is the self”*. And this alone is the ultimate meaning (tātparya) of the Upaniṣads’ sentences.

The quote within the passage (yānubhūtir ajāmeyānantātmā) could be from Vimuktātman’s Iṣṭasiddhi (1.1: yānubhūtir ajāmeyānantānandātmavigrahā |
mahadādijaganmāyācitrabhittiṃ namāmi tām ||).*

Yāmuna’s description seems fair to me. Do readers more expert in Advaita agree?

*I am grateful to Anand Venkatkrishnan for his help in identifying this quote.